Preheat your oven to 400°F (200°C) and line a 12-cup muffin tin with paper liners.

In a small bowl, beat the softened cream cheese, granulated sugar, and lemon zest together until completely smooth. Set aside.

In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, baking powder, and salt.

In a separate medium bowl, whisk the vegetable oil, eggs, milk (or yogurt), lemon juice, lemon zest, and vanilla extract until well combined.

Gently fold the wet ingredients into the dry ingredients until just combined. Be careful not to overmix!

Gently fold in the fresh blueberries using a rubber spatula.

Spoon a small amount of batter into the bottom of each muffin liner. Add a dollop (about a teaspoon) of the cream cheese filling into the center, then top with the remaining batter to cover the filling.

Bake for 18-20 minutes, or until the muffin tops are golden brown and spring back when lightly touched.

Let the muffins cool in the pan for 5 minutes before transferring them to a wire rack to cool completely.